Electric furnace.



J. 0. BOVING.

ELECTRIC FURNACE.

APPLlcArloN FILED SEPT. 4. 1917 1,281,280. Patented oct. 15, 19m

3 SHEETS-SHEET l.

J. BUWNG.

ELECTRIC FURNACE.

APPLICATION FILED. SEPTA. 1911.

3 SHEETS-SHEET 2.

man W Afg'f.

J. 0. BOVING.

ELECTRIC FUHNACE.

APPLICATION man. SEPTA. um.

1,281,280. Patented Oct. 15, 1918.

3 SHEETS-SHEET 3.

.TENS onTEN BovING,

OF LONDON, ENGLAND.

ELECTRIC FURNACE.

Specification of Letters Patent.

Patented Oct. 15, 1918.

Application led September 4, 1917. Serial No. 189,567.

To all whom t may concern.'

Be it known that I, JENs ORTEN BOVING, subject of the King of Great Britain, residing at Imperial Buildings, No. 56 Kingsway, London IV. C. 2, England, have invented new and useful Improvements Relating to Electric Furnaces, of which the following is a specification.

This invention relates to means for utilizing the combined effects of hydraulic and electric'power' to regulate automatically the supply of electricity to an electric furnace.

Theregulation is derived by adjusting the position of the carbon electrode in relation to the molten metal which is being operated on within the furnace, the displacement of the electrode for the purpose being effected by the force of Huid-pressure, on hydraulic operating organs and an elec; tro-magnetic organ provided to command the valvular elements-whereby the supply of pressure-fluid to the said .hydraulic operating organs is so automatically adjusted as to approximate closely to the maintenance of a constant current of electricity through the furnace. i The said electro-magnetic organ is energized by the agency of the electric current which is supplied for the operation of the furnace, a shunt being taken from the main lead for the purpose.'

Alternatively the electro-magnetic organ may be energized by a secondary current derived by a transformer from the main electric current acting as a primary.

Further, alternatively to employing anelectro-magnet and a longitudinally displaced armature thereof as the electromagnetic adjusting organ I may employ a construction such as is used in a single phaserepulsion motor.

By such means I am able to provide a powerful force organ to suitably constrain and displace the carbon electrode which organ is very responsive to fluctuations of the electric current in a manner to causethe fluctuations to be subdued to a. very efficient degree, the electro-magnetic adjusting organ being required to perform merely the duty of regulating the leakage of a small portion of the ressure-fluid past a balanced escape valve t us encountering only a minute resistance to its displacement.

The accompanying drawings show, as a representative example, a form of construction of apparatus possessing the above described features some of the parts therein represented being alternative.

In these drawings Flgure 1 is a sectional elevation of the apparatus,

Fig. 2 is a sectional elevation, on a larger scale, showing the valvular elements employed in maintaining in action the fluidpressure operating organs and showing also one construction of electro-magnetic adjusting device, and:-

Fig. 3 shows a construction a portion of which is alternative to that shown in Fig. 2. Referring to Fig. l, A is the furnace body, B the metal undergoing treatment andC is the carbon electrode. The electrode is carried by an arm D so constructed and provided with rollers (I (l as to be adapted to be vertically displaced with facility along the mast F. The force necessary to readily effect the displacement is provided by means of the xed hydraulic cylinder G and the sliding ram H through the bore of which liquid under pressure is admitted to the cylinder G from a flexible pipe I in a manner to be presently described, the descent of the ram occurring when the liquid is allowed to escape through the pipe J. The ram is secured to the arm D at d1. The high pressure liquid is by the pipe I conducted to the space between the mtwo pistons of a double piston-valve K1 K2 which fits the valve casing L. lVhen the double piston-valve has been displaced downward from the position shown in Fig. 2 the ipe I will be placed in communication wlth the bore of the ram H and liquid under ressure will be able to enter the cylinder and force the ram H and carbon electrode c upward whereas if K1 K2 is displaced upward, the liquid in the cylinder G will be able to escape to the pipe J and permit the ram H and electrode C to descend toward the molten metal B in the furnace A.

The high pressure liquid in the space between K1 K2 will tend to lift K1 K2 by virtue of the larger area of the piston K1. This tendency will be counteracted by the provision of a bore hole k1 through the piston K1 which Will permit the liquid to leak to the space above K1 and press on the upper side thereof. The displacement of the double pistonvalve K1 K2 will be further affected by the provision of a central leakage passage leadmg from the space above K1 to the escape pipe J. This passage is commanded by an escape valve K which is an entirely balanced valve controlled in its operation by an electro-magnetic device to be presently described. Y

In one form of the electro-magnetic device, shown in Fig. 2, I provide two electromagnets M1 M2, M1 being secured to a prolongation of the spindle of the above mentioned escape-valve K which prolongation serves as a solenoid core for the fixed electro-magnet M2.

N is the main electric lead to the carbon electrode. From this a shunt line O is taken to a rheostat P and from this the shunt current is caused to traverse the windings of the electro-magnets M2 M1 and rejoin the main lead N by the lead O1 as shown.

The potential in N at the point from which the shunt line O is taken is sufficiently greater than that at which the shunt current rejoins the main current by the lead O1 to appropriately energize the electro-magnets M2 M1 IVhe'n the current is passing, the magnet M1 will be attracted toward the fixed magnet M2 and tend to close the escape valve K against the compressive force of a spring Q,

which tends to keep the valve open.

When the current in the main electric lead N, and consequently in the shunt O therefrom, has become unduly small on account of the electrode C being insufficiently immersed in the furnace metal B, the spring Q will overpower the pull of the magnet M1 anl raise the escape valve K lthus relieving the pressure in the space above K1. The pressure of the liquid in the supply pipe I will then raise the double piston-valve K1 K2 and permit some of the liquid in the cylinder G to escape and the ram and carbon electrode to descend andncrease the immersion of the latter in the metalB. The raising of K1 K2 will lessen the area of escape past the valve K. At the same time the augmentation of the electric current by the increase of the immersion of the electrode in the metal in the furnace will increase the attraction of the magnet M1.

Thus a very small displacement will cause a correct automatic regulation of the electric current by the interaction of the ram H, the valve K, the piston-valve K1 K2 and the electro-magnet M1.

By the use of the rheostat P a hand adjustment of the current may be superposed on the automatic adjustment and enable the contrivance to be employed under a variety of conditions.

By reference to Fig. 3 an alternative construction of electro-magnetic adjusting device Will be described. In this design, instead of the energizing electric current being. a shunt from the main electric lead to the` carbon electrode as in the arrangements shown in Fig. 2, I may employpa transformer motor.

indicated at R in Fig. 3 to generate a secondary electric current in the wire S, N, as before, indicating the main electric lead to the carbon electrode which is employed by the primary current.-` The secondary current is used to energize an electro-magnetic device which comprises a construction T such as is employed in a single-phase repulsion strained by a spring U which reverses the rotor when the electric current is relaxed.

Y To the rotor a cam V of gradually increas- S and correspondingly regulate the Iiosi` tions of the valvular elements K, K1

1. An apparatus'for maintaining a constant current through an electric furnace comprising fluid pressure means for modif-1yin the position of the furnace electro e, va vular elements for regulating the supply of fluid to Xsaid means, electro-magnetic means controlling said valvular elements, and a source of current having a circuit including said electro-magnetic means and the furnace electrode in a manner to effect an automatic adjustment of said valvular eled ments by said electro-magnetic means.

2. An apparatus for maintaining a constant current through an electric furnace comprising fiuid pressure means for modif inl the position of the furnacev electro e, va vular elements for controlling the supply of fluid to said fluid pressure means and actuated by the fiuid, a source of current', a circuit including said source of current and the furnace electrode, and an electrorespon sive device included in said circuit in ,such

manner that the supply of current thereto is in accordance 'with the position of the furnace electrode, whereby the position of the valvular elements would be automatically adjusted.

3. An apparatus as described in claim 1, and a balance escape valve actuated by said electro-magnetic means for controlling the movements of the valvular elements.

4. An apparatus for maintaining a con-- stant current through an electric furnace comprising Huid-pressure means for modi- .fylng the osition of the furnace electrode,

valvular e ements actuated by the fluid-pres- The rotor element of T 1s conf sure means regulating the 'supply ofy fluid to said Huid-pressure means, a balance escape valve for controlling the passageof fluid to said valvular elements, a source of current, a transformer, an electro-respon- .l

sive device energized by said transformer andbased to a predetermined position, and a circuit includlng said source \of current, said transformer, said furnace electrode, and said electro-magnetic means in such manner that an automatic adjustment of the escape valve by means of said electromagnetic means is effected.

5. An apparatus as described in claim 4, and a rheostat included in said circuit for controlling the supply of current through .said electro-magnetic means.

6. In combination, an electric furnace -including an electrode, means for adjusting the position of said electrode, fluid-pressure means for actuating said means, valves for controlling said Huid-pressure meansv and biased to a predetermined position, cam-actuated means for moving said valves against their bias, electro-magnetic means for contion, an escape valve for controlling thc said electro-magnetic means and the furnace electrode.

7. In combination, an electric furnace including an electrode, fluid-pressure means for adJusting the position of said electrode, valves for controlling the fluid-pressure means and biased to a predetermined posimovement of said valves, electro-magnetic means for controlling said escape valve coniprising a solenoid and an electro-magnet, a source of current having a circuit including said electro-magnetic means and the furnace electrode, and means for manually controlling said electro-magnetic means.

In testimony whereof I have signedmy name to this specification in the presence of two subscribing witnesses.

`.mus QRTEN BovING.

Witnesses:

' W. LANE,

M. C. Rooms. 

